Athletic footwear generally includes an upper and a sole structure. Usually formed of leather, synthetic materials, or a combination thereof, the primary purpose of the upper is to comfortably secure the wearer's foot to the sole structure while providing necessary ventilation and protection from the elements. The sole structure is attached to the upper and typically has a multi-layer construction which includes a sock liner (insole), midsole, and outsole. The sock liner is located within the upper and improves the comfort of the footwear. The midsole forms the cushioning layer of the sole and may be formed of a soft, yet resilient foam material that attenuates the impact forces of running, walking, or other movement. The outsole may be fashioned from a durable synthetic, such as rubber, to resist wear during use and includes spikes and ridges.
Although the upper and sole structure may be considered universal elements of athletic footwear, the specific sport for which footwear is intended to be used determines the individual, specialized characteristics of each element. Commonly, running shoes include lightweight elements that minimize the harmful effects of over-pronation; basketball shoes require components that stabilize the foot during quickly-executed direction changes, jumps, and stops; and football shoes incorporate cleats to ensure adequate traction on a natural turf surface. Accordingly, the primary differences between sport-specific styles of athletic footwear relate to the highly-refined features that make footwear appropriate for the demands of a particular sporting activity.
Shoes for track, in particular for passing over hurdles, also include a highly-refined set of elements that combine to form an article of footwear having characteristics specific to the track. The ideal track shoe includes a low profile design that provides little or no support for the shoe. In general, the thicker the sole of an article of footwear, the more unstable the footwear becomes. A low profile design thereby lends stability to an article of track footwear. A track shoe generally has spikes on the forward portion of the shoe to aid in traction, but is otherwise made of a smooth, slippery, material.
Often, when hurdling, the heel portion of the bottom of the shoe contacts the hurdle. Such contact can slow down the hurdler or make the hurdler trip and possibly fall.